The present invention relates to a data transfer control device and an electronic instrument.
In recent years, a high-speed serial interface standard such as the Universal Serial Bus (USB) or IEEE1394 has attracted attention. A data transfer control device has been known which has a bus bridge function between a high-speed serial interface bus (e.g. USB bus) and an AT Attachment (ATA) bus to which a storage (e.g. hard disk drive (HDD)) is connected (JP-A-2002-344537). According to such a data transfer control device, data can be written into the HDD through the USB bus at high speed, or data can be read from the HDD at high speed.
However, in such a data transfer control device, it is necessary to incorporate a USB protocol control program into firmware which operates on a main CPU of an electronic instrument. Therefore, since the designer of the electronic instrument must understand the USB protocol control to a certain extent, the design work becomes complicated, or the support business of the manufacturer of the data transfer control device becomes complicated.
A high-speed serial interface circuit such as a USB serial interface circuit may be incorporated as an Intellectual Property (IP) core depending on the type of main CPU.
However, an analog circuit (physical layer circuit) for transmitting and receiving data at high speed is provided in the high-speed serial interface circuit, and may decrease the yield of the main CPU. Moreover, since the circuit design of the high-speed analog circuit is difficult and requires know-how, a situation may occur in which the transfer rate provided in the standard cannot be realized, whereby data cannot be written into or read from the HDD at high speed.